JPH02170590A - Light storing ring - Google Patents

Abstract

PURPOSE:To enable the enhancement of light rays of specified wavelength by a method wherein a stored synchrotron radiation and orbiting charged particles are made to interact under a special condition to enable a laser oscillation to start. CONSTITUTION:The radiuses of curvature of a reflective mirror 2 and an electron orbit 1 are set to specified values respectively to enable a laser oscillation to start taking advantage of a synchrotron radiation(SOR) stored in a light storing ring and an electron beam, and a diffraction grating 8 is provided to a part of the reflective mirror 2 to start a laser oscillation. That is, the diffraction grating 8 is provided to a part of the reflective mirror 8 to start a laser oscillation inside the light storing ring using light rays of specified wavelength as a seed which are selected and directed in a predetermined direction through the diffraction grating 8. Here, the predetermined direction is a direction in which the light rays of specified wavelength travel touching the electron orbit 1, and the diffraction grating 8 is so provided as not to make the light rays travel in a direction aligned with the connecting direction of a light outlet 3. By this setup, a laser oscillation is made to start to remarkably increase projection light rays in intensity, and light rays with a specified wavelength lambda are amplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a light storage ring using a synchrotron radiation light generating device.

[Prior art] Conventionally, synchrotron radiation is generated in the tangential direction of the orbit by moving charged particles at a speed close to the speed of light along a trajectory with a predetermined curvature, and the synchrotron radiation is arranged so as to surround the outer periphery of the orbit. A light storage ring has already been proposed, which includes a reflecting means for reflecting synchrotron radiation light and a light extraction means for extracting the synchrotron radiation light accumulated in the reflection means as emitted light. (Special application 1986-228
See specification No. 543. ) [Problems to be Solved by the Invention] However, in the conventional optical storage ring, it is not possible to effectively utilize the synchrotron radiation light (SOR light) by simply accumulating the synchrotron radiation light (SOR light) within the optical storage ring. It does not amplify or oscillate the accumulated light. Therefore, the emitted light collected from the light extraction means is shown in Fig. 4 (
As shown in a), it has continuous wavelengths.

Therefore, an object of the present invention is to provide an optical storage ring having means for amplifying the light accumulated in the optical storage ring and causing laser oscillation to dramatically increase the intensity of the emitted light. By this means, the emitted light is not changed to a specific wavelength λ, as shown in FIG. 4(b). It is expected that the light with its harmonics will be amplified and made monochromatic.

[Means for Solving the Problems] The optical storage ring according to the present invention generates synchrotron radiation in the tangential direction of the trajectory by moving charged particles at a speed close to the speed of light along a trajectory with a predetermined curvature. death,
A light storage ring having a reflecting means disposed around the outer circumference of an orbit to reflect synchrotron radiation, and a light extraction means for extracting the synchrotron radiation accumulated in the reflecting means as emitted light, It has an oscillation means that amplifies light with a specific wavelength and causes laser oscillation by interacting the accumulated synchrotron radiation light with orbiting charged particles under special conditions.

A component of the oscillating means may be a selection means for selectively reflecting particular wavelengths of the accumulated synchrotron radiation.

As this selection means, for example, one in which part or all of the reflection means is made of a diffraction grating can be considered.

Alternatively, the oscillation means may be configured with means for injecting a laser beam into the reflection means as a component of the oscillation means.

[Example 1] Referring to FIG. 1, a light storage ring to which the present invention is applied has a synchrotron radiation light generating device, a reflecting mirror 2 surrounding the outer periphery of the synchrotron radiation generating device, and a pre-extraction port 3.

The electron beam trajectory (electron trajectory) 1 and the reflecting mirror 2 are configured so that their centers of curvature are equal.

In the first embodiment of the present invention, the radius of curvature of the reflecting mirror 2 and the radius of curvature of the electron trajectory 1 will be described later in order to perform laser oscillation using synchrotron radiation and electron beams accumulated in the optical storage ring. A diffraction grating 8 is disposed on a part of the reflecting mirror 2 in order to set it to a certain specific value and cause laser oscillation.

The radius of curvature of the reflecting mirror 2 is calculated as follows.

The synchrotron radiation emitted in the tangential direction from the electron orbit 1 is reflected by a reflecting mirror 2 concentric with the electron orbit 1 and comes into contact with the electron orbit 1 again. In the optical storage ring, electrons are grouped into pulsed bunches and circulate on an electron orbit 1. Therefore, a special relationship is required between the radius of curvature of the electron trajectory 1 and the radius of curvature of the reflecting mirror 2 in order for the reflected light to reunite with the electrons and cause the electrons to undergo stimulated emission of light.

By the way, since the speed of electrons and the speed of light are approximately equal, it is almost impossible for the first bunch 6 that has emitted light to be reunited with that light. However, it is possible for a second bunch 7 different from the first bunch 6 to orbit on the electron orbit 1 and reunite with the light.

From the generation point A on the electron trajectory 1 where the SOR light is generated, the SOR light is reflected at the reflection point B of the reflecting mirror 2, and the SOR light is reflected from the generation point A on the electron trajectory 1.
The distance that the SOR light travels to the arrival point C where it contacts is assumed to be 2d. A straight line O connecting the center of curvature 0 of the electron trajectory 1 and the reflection point B
The included angle between B and the straight line OA that connects the center of curvature O and the point of occurrence A, and the straight line O that connects the straight line OB, the center of curvature O, and the arrival point C
Let the included angle with C be θ as shown in the figure. Then, conditions are determined for the SOR light generated from the first bunch 6 to be reflected by the reflecting mirror 2 and reunited with the second bunch 7.

The SOR light generated from the first bunch 6 at the generation point A is reflected at the reflection point B of the reflecting mirror 2, and this reflected light is transmitted to the electron trajectory 1.
It touches at reaching point C. At this time, it is sufficient that the second bunch 7 is also at this arrival point C. That is, during this time, the SOR light travels a distance of 2d with its speed being C, and the second punch 7 travels by 2rθ+nπr with its speed being V. 2d
-2rtan θ, so the condition for making the optical storage ring oscillate is that light and electrons first meet again at a precise period. It is expressed by the following formula.

(2rθ+nyrr) bar (2r tanθ)/c-0
...(1) Here, it is assumed that the electron orbit 1 is a perfect circle. And 2
It is assumed that the machine is operating with two punches (first punch 6 and second punch 7). n (≧1) is an integer and means that the punch is n backwards.

Incidentally, there is the following relationship between the radius R of the reflecting mirror 2 and the radius of the trajectory 1 of the punch.

R#r/cosθ−(2)
When operated in such a way that the SOR light is reunited with the punch, it is expected that a very powerful laser beam with a short pulse width will be generated. To go into more detail, it is generally known that when light such as SOR light interacts with electrons, the light is absorbed by the electrons, or the electrons induce the emission of light, and the light is amplified. There is. Whether light is absorbed by electrons or amplified depends on the relative positional relationship with respect to the phase of the electrons and light.

However, although the above-mentioned conditions for the reunion of the light and the punch are necessary conditions for causing laser oscillation, laser oscillation does not occur if these conditions alone do not cause laser oscillation. When laser oscillation occurs within the optical storage ring, the rotating punch must have a density of electrons that corresponds to the wavelength of the oscillating light. Conversely, the grown laser light creates a density of electrons, and unless this continues, laser oscillation will not occur. However, the density of electrons is formed with respect to a specific wavelength, and if light of various wavelengths interacts with the punch, a specific density of electron density will not be formed. In other words, the wavelength of this light is not specified from the above equation (1). Equation (1) is satisfied at any wavelength. Furthermore, unless the phase relationship between the punch and the oscillation light is constant at all times, the density of electrons cannot be maintained. In order for electrons and light to reunite and for light of a specific wavelength to maintain an acceleration or deceleration phase, it is necessary that the phase of this density and the phase of the light match each time.

Next, a description will be given with reference to FIG.

FIG. 3 is a diagram showing how electrons approach from the perspective of light when the path of light is taken along two axes.

Spontaneous synchrotron radiation (SOR light) comes out from the top of orbit 1 of the electron's radius in Figure 3, and then reunites with the electron at the top.

However, when light and electrons interact at the contact point, the electric field created by the light is perpendicular to the electrons, so the electrons are not affected in the direction of their movement by the electric field created by the light.

Therefore, in this case, the electrons are neither decelerated nor accelerated.

However, when electrons and light meet again at an angle,
The electric field created by light has a component in the direction in which the electrons travel, so the electrons are decelerated or accelerated. Stimulated emission of light from electrons occurs when the electrons are decelerated. Therefore, the condition under which stimulated emission of light occurs repeatedly and laser oscillation occurs is when light interacts with electrons through the inner orbit z1 in FIG. 3. That is, in the state of laser oscillation, the light passes through a path slightly inside the orbit 1 of the electron radius r.

By the way, if light and electrons are in a deceleration phase in the first quadrant of Figure 3 and enter the second quadrant with the same phase, then in the second quadrant there is an Since the direction of the component is reversed, it changes to an acceleration phase. In other words, while the quadrants change, more precisely, from the point where light and electrons intersect in the first quadrant to the point where light and electrons intersect in the second quadrant, the phase of light and the density of electrons change. If the phase is shifted by half a wavelength, the deceleration phase will continue. Continuation of the deceleration phase is a condition for laser oscillation to occur.

However, in reality, there are many types of light that have wavelengths that satisfy the condition that the phase of the light and the phase of the density of electrons are shifted by half a wavelength while traveling from the first quadrant to the second quadrant. In particular, since the 2'-axis trajectory can be drawn arbitrarily, the wavelength of the light is not determined in that sense either. Therefore, in a state where oscillation is occurring, the wavelength of light becomes longer as it travels inside orbit 1 with radius r of the electron.

In order to cause laser oscillation, it is necessary to select a specific wavelength and form the punches with density as described above. Therefore, when laser oscillation occurs, the following equation must be satisfied.

L X (c v *) / c-λ/2
(3) Here, L is half the length of the path through which the light passes inside the circumferential orbit of the punch with radius r, and ■ is the average velocity of the electrons in the two-axis directions.

However, when the laser is oscillating, it must be at a specific wavelength, but equation (3) can take various values by changing the 2" axis orbit, so from this equation, the oscillation wavelength is unique. Normally, in a six-electron laser using an undulator, the oscillation wavelength is uniquely determined by the period of the magnetic field that changes polarity alternately, but in oscillation by an optical storage ring, the oscillation wavelength is uniquely determined by the period of the magnetic field that changes polarity alternately. Since it is not used, the wavelength of the light is not determined.

As mentioned above, in order to cause laser oscillation using a light storage ring, a mechanism is required to select light with as narrow a spectrum width as possible. As one method for this purpose, in the first embodiment, the diffraction grating 8 is disposed on a part of the reflecting mirror 2, as described above. It is known that the diffraction grating 8 selectively reflects only specific wavelengths in a predetermined direction. Laser oscillation can be caused within the optical storage ring using the light of a specific wavelength selected by the diffraction grating 8 as a seed. It goes without saying that this predetermined direction is a direction in contact with the electron orbit 1, specifically, a direction in contact with an orbit slightly inside the electron orbit 1. Also,
The diffraction grating 8 is arranged so that this predetermined direction does not coincide with the tangential direction of the pre-extraction port 3 direction. This is because, when arranged in this manner, light of a specific wavelength selected by the diffraction grating 8 is not amplified within the optical storage ring. In this way, the diffraction grating 8 plays the role of selecting a specific wavelength and aligning the phases.

Incidentally, the entire reflecting mirror 2 may be replaced with the diffraction grating 8.

[Embodiment 2] FIG. 2 is a schematic plan view for explaining the principle of a light storage ring according to a second embodiment of the present invention.

In the second embodiment, unlike the first embodiment described above, the diffraction grating 8 is not disposed in a part of the reflection wIL2, and the laser input is performed to input a laser beam having a specific wavelength from the laser device 5. The opening 4 is provided on the reflecting mirror 2, and the laser beam is applied along the tangential direction of the electron trajectory 1 (more precisely, the trajectory slightly inside the electron trajectory 1), but other than that, this is the same as the first embodiment. It is similar to Laser oscillation can be caused within the light storage ring using this injected laser light as a nucleus. Thereby, it is possible to select a specific wavelength of the emitted light and to align the phases.

Configure the optical storage ring as described above, and replace part or all of the reflecting means with a diffraction grating as shown in FIGS. 1 and 2, or inject a laser beam into the reflecting means. Therefore, if light of a specific wavelength is selected, the density corresponding to that wavelength is formed into a punch, and the phase of the density of the punch and the position of the light are as follows: Since they are configured to shift by half a wavelength, the deceleration phase continues and light amplification occurs. That is, it can be seen that laser oscillation can be performed. Furthermore, such a condition holds true everywhere on the optical storage ring. As shown in Figures 1 and 2, two points a on the electron orbit 1
, b emerge at different times, pass the same time, and meet the same punch again at different times. After they meet again at point a', there is a lapse of time until they meet again at point b'', and at point b'' the light and electrons can again be in the same phase condition. In this way, if part or all of the reflecting means is replaced with an aperture grating, or if laser light is applied to the reflecting means, all the SOR light accumulated in the optical storage ring will be converted into coherent laser light. Conceivable.

This laser light is then continuously emitted from the pre-extraction port 3.

[Effects of the Invention] As is clear from the above description, according to the present invention, part or all of the SOR light reflecting means arranged to surround the outer periphery of the orbit having a predetermined curvature of a charged particle is diffracted. Laser oscillation can be caused within the optical storage ring by replacing it with a grating, or by providing a laser input port for inputting the laser beam into the reflecting means and inputting the laser beam from the laser beam input port. There is an effect. Therefore, among the light emitted from the light storage ring, light having a specific wavelength increases and becomes monochromatic.

FIG. 2 is a diagram showing the relationship between wavelength and intensity.

1... Circumferential orbit of the electron beam, 2... Reflector, 3...
...Light extraction port, 4...Laser input port, 5...Laser device, 6...First punch, 7...Second punch,
8... Diffraction grating.

[Brief explanation of the drawing]

1 is a schematic plan view for explaining the principle of a light storage ring according to a first embodiment of the present invention, and FIG. 2 is a schematic plan view for explaining the principle of a light storage ring according to a first embodiment of the invention.
FIG. 3 is a schematic plan view for explaining the principle of a light storage ring according to an embodiment of the present invention, FIG. 3 is a diagram for explaining the conditions under which the light storage ring of the present invention oscillates, and FIG. Outgoing light Figure 3 Figure 4 Outgoing light 3 lengths of length 3 inches ahead of the extension procedure amendment export) 242nd, 1995

Claims (4)

[Claims] (1) By moving a charged particle at a speed close to the speed of light along a trajectory with a predetermined curvature, synchrotron radiation is generated in the tangential direction of the trajectory, and synchrotron radiation is arranged so as to surround the outer periphery of the trajectory. In a light storage ring having a reflection means for reflecting the synchrotron radiation light and a light extraction means for taking out the synchrotron radiation light accumulated in the reflection means as output light, the accumulated synchrotron radiation light and A light storage ring characterized in that it has an oscillation means that amplifies light having a specific wavelength and causes laser oscillation by causing charged particles orbiting in the orbit to interact with each other. (2) The optical storage ring according to claim 1, wherein a component of the oscillation means is selection means for selectively reflecting a specific wavelength of the accumulated synchrotron radiation light. (3) The light storage ring according to claim 2, wherein part or all of the reflection means as the selection means is made of a diffraction grating. (4) The optical storage ring according to claim 1, wherein a component of the oscillation means is means for injecting laser light into the reflection means.